An electrophotographic image forming apparatus such as a copying machine and a printer has been conventionally provided with a fixing device by which a toner image is fixed onto a sheet of paper.
The fixing device includes, for example, a fixing roller and a pressurizing roller that is pressed against the fixing roller. The fixing device fixes the toner image onto the sheet of paper by heating and pressurizing the sheet of paper in a fixing nip formed between the fixing roller and the pressurizing roller. Moreover, the fixing device of such configuration includes a separation claw that is in contact with the fixing roller, the separation claw being used to separate the sheet of paper, onto which the toner image is fixed, from the fixing roller.
Normally, the aforementioned separation claw is in contact with the fixing roller at all times. Thus, a portion on the fixing roller in contact with the separation claw gets locally worn down, thereby causing a toner to get into the worn portion and generating a poor image. Now, there has been disclosed in Patent Document 1 a configuration which attempts to prevent the local wear on a fixing roller by alternating a separation claw to be brought into contact with the fixing roller in a fixing device including a plurality of separation claws.
[Patent Document 1] Japanese Unexamined Patent Application, Publication No. H07-261589